Recent studies have documented increased prevalence of dental fluorosis in the United States and Canada due to widespread ingestion of fluoride during tooth development, both from fluoride used for caries prevention and from water, beverages and foods. In this study, longitudinal assessment of dietary and non-dietary fluoride exposures will continue using previously collected data, and from continued data collection at 6-month intervals, on a birth cohort aged 73-107 months at the beginning of the proposed renewal. Parents will continue to provide detailed data on their children's fluoride exposures and ingestion via written questionnaires and 3-day dietary diaries. Composite indices of fluoride intake will be obtained. Dental fluorosis and caries prevalence and severity in the mixed dentition will be assessed at age 8 1/2 to 9. Primary specific aims are to: 1) continue to assess dietary and non-dietary fluoride exposures, 2a) determine the prevalence and severity of dental fluorosis in the early erupting permanent dentition, 2b) assess relationships between early-erupting permanent tooth dental fluorosis and longitudinally recorded fluoride exposures and ingestion levels, and 3) assess the relationships between the prevalence and severity of dental fluorosis of the early-erupting permanent dentition and the prevalence and severity of fluorosis of the primary dentition.